1. Field of the Invention
The present invention relates in general to a cutting device for elongated materials and, more particularly, to a portable cutting device that attaches to a sewing machine for cutting thread, shoulder tape and the like.
2. Description of the Related Art
Materials used in the manufacture of clothing, such as cotton, polyester and rayon are typically coupled by thread to form a seam. Thread is also used for other purposes such as decoration, labeling and the like. In some textile applications, such as the manufacture of shirts, pants and jackets, shoulder tape extends along a seam to provide reinforcement, flexibility and/or discreteness to the seam. Shoulder tape may be adhesive or nonadhesive and has a typical width of about 5-15 mm and thickness of about 1-3 mm.
Thread and shoulder tape are typically provided in spools of about 25-1,000 yards. Because only a portion of the thread or shoulder tape stored on the spool is required for a particular use, the material must be separated from the spool. When separating the material from the spool, speed, accuracy, safety and cost are important considerations.
One way of separating the material from the spool involves manually cutting the thread with a knife or scissors. However, this procedure takes a significant amount of time and is therefore disadvantageous in commercial clothing manufacturing operations. Another way of separating the material involves an automated knife or scissors. However, automated scissors tend to be sensitive to wear, among other disadvantages, and also tend to be unsafe.
For example, U.S. Pat. No. 4,130,038 issued to Zehnder apparently discloses an automated knife and thread parting device for textile machines. The device has a fixed separating member and a cutting member. The fixed separating member comprises two mutually parallel and mutually spaced thread guide plates. The cutting member comprises a U-shaped thread tensioning bow with spring clamping shanks. A blade is arranged on the cutting member between and parallel to the spring clamping shanks. Although this configuration provides a device that can separate thread, it has significant drawbacks that include: creating a significant likelihood that an operator""s finger may be accidentally caught within the device and cut, as well as causing slippage of the thread during the cutting sequence which results in an inaccurate lengthwise cut. The latter shortcoming is particularly evident when used to cut thicker, wider nonthread materials such as shoulder tape.
There is thus a need for a cutting device for elongated materials that improves the speed, accuracy, safety and cost associated with the devices disclosed in the prior art. There is also a need for a cutting device that easily and accurately cuts a variety of elongated material, to include thread and shoulder tape.
The present invention provides a cutting device for elongated materials comprising a first block or ram, and a second block or receptacle. The ram has a channel that extends along its longitudinal length, the channel is sized and configured to accept at least a portion of a cutting blade. The receptacle has a hollow that is sized and configured to accept at least a portion of the ram. The blade is arranged within the hollow and extends from the receptacle into the hollow and toward the ram. The blade is advantageously recessed within the hollow.
In one embodiment, the ram is moveable between a retracted position, in which the ram is separated from the receptacle, and an extended position, in which at least a portion of the ram is housed within the receptacle. By this configuration, elongated material may be placed between the receptacle and ram and then the ram can move from the retracted position to the extended position, whereby a portion of the elongated material is captured within the channel and cut by the blade.
One aspect of the invention involves a cutting device for elongated materials having a safety feature to inhibit the cutting device from accidentally cutting a person""s finger. The cutting device comprises a first block defining a channel within at least a portion of the first block, the first block being moveable between a first position and a second position. A second block defines a hollow within at least a portion of the second block, the hollow sized and configured to accept at least a portion of the first block when the first block is in the second position. The cutting device advantageously has a cutting blade recessed within the second block so as to inhibit contact with a person""s finger if the person""s finger is placed between the first block and the second block, at least a portion of the cutting blade capable of fitting within the channel of the first block.
Another aspect of the invention involves a device that attaches to a sewing machine for cutting elongated materials, comprising a hydraulic drive attached to the sewing machine and moveable between a retracted position and an extended position; and a ram connected to the drive, the ram having a channel within at least a portion of the ram that extends along an outlet to assist in removing build-up of excess material that has been cut by the device; and a receptacle attached to the sewing machine, the receptacle having a hollow within at least a portion of the receptacle that accepts at least a portion of the ram when the ram is in the extended position and a blade recessed within the receptacle.
Yet another aspect of the invention involves a method for filing materials to form a hem comprising the steps of: interposing the material between a ram and a first recess; moving at least one of the ram and first recess to force the material into the first recess; urging the material against a cutting blade in the first recess; and moving the material and cutting blade into a second recess located in the ram to cut the material.
The cutting device of the present invention thus provides a fast and inexpensive way for separating a variety of elongated materials, in part because of the cutting blade. The device also provides accurate cutting of elongated materials by inhibiting movement of the material during the cutting sequence, in part because of the arrangement of the channel walls of the ram and the channel walls of the receptacle. The device further provides for operator safety by using an unexposed blade recessed within a relatively narrow hollow. The device is also long-lasting since the recessed blade less exposed and therefore a large number of cuts may be made before the blade dulls.
Further aspects, features and advantages of the present invention will become apparent from the drawings and detailed description of the preferred embodiments that follow.